In the first case, is it voluntary if the shop owner fails to point out that the brand I do want is there, but is hidden? How about if I explicitly ask him for it? Or if I am clearly an uninformed water customer, and don't know that the brand of water I am buying is nowhere near as good quality as the other brand he hasn't told me about?
For the other two cases I agree with your assessment, though I'm not sure that it is strictly "rational to extend basic good will to others". I do think that is the right course of action, I just don't think it is rational. That kind of behaviour is rational in situations where it might be reciprocated, but when no-one is going to know either way, I think that good will is only extended as a cultural artifact (which is a very good thing!)
> In the first case, is it voluntary if the shop owner fails to point out that the brand I do want is there, but is hidden?
You can either buy it or leave it. The decision to buy any brand is voluntary.
As for the guy selling you a water bottle when you're dying of thirst, it depends. What's he asking for it? $1.00 for a bottle of water when you're dying of thirst? -Seems reasonable. But demanding $1 million for the water would not be. Is the exchange voluntary?
If you've got two options: A) Buy water, or B) Die, it kind of works both ways. Theoretically it's voluntary, because you can just choose to die instead, but in practice, you would do whatever it takes to get that water.
But what does it matter if that particular exchange is voluntary or not? Basically, you just started picking apart my original statement that "voluntary exchanges are the basis of all economic activity ever", but to what end?
>> In pretty much every exchange we make there is an asymmetry of information, and that asymmetry can and is exploited to make 'unnatural' gains. This is most obviously so if you reduce it to the absurd and imagine an entity that controls all information - there is clearly the possibility of coercion, in the sense of convincing you to make exchanges that you wouldn't otherwise. Given the profit-seeking nature of our system, the possibility in the absurd case becomes a near certainty even in the limited case, as people are incentivised to manipulate each other to induce favourable exchanges.
We're all actively pursuing our personal gain through whatever (voluntary) exchanges we decide to participate in, but it's important to note that there's no absolute value to be assigned on each side of some specific trade that's about to occur. The value an exchange offers you is partially subjective, and therefore varies case by case.
It's enough that both parties in an exchange consider it acceptable. In other words, both parties perceive enough benefit in the exchange to actually go through with it. Otherwise they'd just move on to find something else.
This works out beautifully, because a business will always sell its product to you at a price higher than what it cost to produce[1], but at the same time, you value your gain higher than the loss of your money. Both parties benefit.
[1] Otherwise the business would go out of business.
>> Given the profit-seeking nature of our system
It's not the "system's" nature to be profit-seeking - it's human beings'. The pursuit of personal gain applies to each and every one of us, and happens to be the reason why there are any businesses (& jobs!) at all.
For the other two cases I agree with your assessment, though I'm not sure that it is strictly "rational to extend basic good will to others". I do think that is the right course of action, I just don't think it is rational. That kind of behaviour is rational in situations where it might be reciprocated, but when no-one is going to know either way, I think that good will is only extended as a cultural artifact (which is a very good thing!)